Trench digging machine



y 1967 w. B. PERRY ETAL 3,319,365

TRENCH DIGGING MACHINE 2 Sheets-Sheet 1 Filed Nov. 23, 1964 a /7 .FZ'GZ. Z 26 33 FIG? 3. 84

Y y 5mm w n W10, T 1 1 E5 w A E mmof.

.7 B 7 a b, .V .2 L. 0 0 .9 4 9 W 2 QJZOWWLJJ 4 @a 5 6 y 1967 w. B. PERRY ETAL. 3,319,365

TRENCH DIGGING MACHINE Filed Nov. 23, 1964 2 Sheets-Sheet 2 I N VEN'IORS Mun-"E B. Pee/2y 0 M4L0 L. AWL-"SAY United States Patent 3,319,365 TRENCH DIGGING MACHINE Walter B. Perry, 403 W. Elmwood, and Donald L. Livesay, 27008 Cornell, both of Hemet, Calif. 92343 Filed Nov. 23, 1964, Ser. No. 412,968 4 Claims. (Cl. 37-94) The present invention relates to a machine for cutting a narrow trench in the ground to a depth of several inches, for the purpose of installing Water pipe for underground irrigation systems, burying cables, and the like.

The primary object of the invention is to provide a new and improved machine of the class described, which is supported by rubber-tired wheels and in which the cutting wheel is driven by an internal combustion engine, so that it needs only to be propelled and guided by the operator.

Another object of the invention is to provide a trenchdigging machine that deposits the pulverized soil that is dug up in a neat, compact pile immediately alongside the trench, where it can be quickly and easily pushed back into the trench to cover the water pipe and refill the trench.

A further object of the invention is to provide a trenchdigging machine that is convenient and easy to use, sturdily constructed, readily adjustable to depth of cut, and easy to service.

Still another object of the invention is to provide a machine of the class described having a vertical digging wheel enclosed within a protective shroud, wherein the cutting blades, the digging wheel, and the configuration of the shroud are so arranged and designed that the cutting blades dig a narrow trench in the ground and throw the pulverized soil rearwardly and to one side, while the shroud deflects and guides the flying soil so that it is deposited in a narrow pile close alongside the trench, Without using conveyors or other apparatus.

These and other objects and advantages of the present invention will become apparent to those skilled in the are upon consideration of the following detailed description of the preferred embodiment thereof, reference being had to the accompanying drawings, wherein:

FIGURE 1 is a side elevation of a trench-digging machine embodying the principles of the invention;

FIGURE 2 is a top plan view of the same:

FIGURE 3 is an elevation of the machine, as seen from the other side;

FIGURE 4 is an enlarged sectional view, taken at 44 in FIGURE 1;

FIGURE 5 is a horizontal sectional view, taken at 55 in FIGURE 1; and looking down into the machine;

FIGURE 6 is a vertical sectional view taken at 6-6 in FIGURE 5; and

FIGURE 7 is an enlarged sectional view of a detail, taken at 77 in FIGURE 6.

In the drawings, the machine of the invention is desig nated in its entirety by the reference numeral 10, and comprises a frame 12, having upwardly and rearwardly bent, tubular steel handlebars 14 and 15. The frame 12 is supported on a pair of laterally spaced rear wheels 16 and 17, and a front wheel 18, the latter being disposed ahead of and slightly inwardly of the left-hand rear wheel 17.

The frame 12 also includes a platform 20 of steel plate, having downwardly extending sides 21 and 22. Mounted on the platform 20 is an air-cooled gasoline engine 23 having a transversely disposed drive shaft 24. A clutch on the drive shaft 24 at the left-hand side of the engine drives a dual V-belt pulley 26. The clutch 25 is engaged and disengaged by means of a control lever mounted on the handle 15, and control lever 30 is connected by linkage 31 to one end of a pivoted lever 32, the other end of which is connected to an actuating member 33 projecting endwise from the clutch 25,

Trained around the dual V-belt pulley 26 are two V- belts 34, which extend downwardly and slightly forwardly, and pass around a large dual V-belt pulley 35. The pulley 35 is mounted on a shaft 36 which extends .transversely of the machine and is journaled in bearings 37 mounted on the platform sides 21, 22, as best shown in FIGURE 5.

Mounted on the shaft 36 midway between the platform sides 21, 22, is an elongated housing 40 containing sprockets 41 and 42 (FIG. 3), which are connected by a chain 43. The housing 40 is a box-like structure of steel plate having aligned bearings 44 mounted on opposite sides near one end thereof. The shaft 36 passes through the bearings 44 and is rotatable therein. Sprocket 41 is mounted on the shaft 36, while the other sprocket 42 is mounted on a short shaft 45 which is journaled in a bearing 46 on the right-hand side of the housing 40 near the other end thereof. The projecting end of the shaft 45 is shouldered at 51, and a star-shaped cutting wheel 50 is clamped against the shoulder 51 by two lock nuts 52, which are screwed onto a threaded stud portion 53 forming the outer extremity of the shaft.

The cutting wheel 50 turns in a clockwise direction as viewed in FIGURES 1 and 6, and the leading edge 54 of each of the star points 55 is inclined back at an angle of about 10 degrees to a line drawn radially from the center of the wheel. The leading edge 54 is also beveled at an angle of about degrees to the plane of the Wheel 50, as shown in FIGURE 7, and welded to this beveled edge is a backing plate 56. Knife blades 60 are secured by screws 61 to the front side of the inclined backing plate 56, and the outer ends of the blades 60 are bent forwardly at a slight angle to form a lip 62. The forwardly bent outer ends of the blades 60 are also flared outwardly a small amount, so that the cutting edge at the outer end of the blade is slightly wider than the rest of the blade, and therefore cuts a trench that is slightly wider than the main body of the blade, as shown in FIGURE 4. This prevents the cutting wheel from binding in the trench when the machine is turned slightly in one direction or the other while following a line that curves or wanders somewhat.

The top half of the cutting wheel 50 is enclosed within a protective shroud 63, that is secured to the housing 40 by screws 64. The shroud 63 is constructed of heavy gauge sheet steel with laterally spaced, parallel side walls 65 and 66, and an arcuately curved outer wall 70. As best shown in FIGURE 6', the right-hand side wall 66 is cut away at 71 along a line substantially radial from the center of the cutting wheel :50, so that the wall 66 has the general configuration of a sector equal to approximately one-quarter of a full circle. FIGURE 5 shows that the wall 66 is not exactly parallel to the left-hand wall 65, but, instead, diverges very slightly to the rear, with an included angle between them of about 3 degrees. A deflector blade 72 is welded to the outer surface of the wall 66 along the edge 71, and this deflector blade is disposed at an angle of about 25 degrees to the wall 66.

Another deflector blade 73 having the general configuration of a spiral ramp, is welded at 74 to the left-hand shroud wall 65, and at 75 to the rear edge 71 of wall 66. The outer edge of the spiral ramp deflector 73 is shaped to conform to the inner surface of the outer shroud wall 70, and is welded thereto. The inner edge 76 of the deflector 73 is a circular arc, the center of which is at the wheel center, so that the edge 76 is spaced equidistantly from the outer end of the blade 60 for all positions of the blade as it sweeps past the edge.

Also welded to the outer wall along the right-hand Fateiited- May 16, 1967 edge thereof, from the bottom of the shroud 63 to a point a short distance ahead of the center, is an inclined, outer deflector wall 80, which defines one side of an exit chute through which the pulverized soil is thrown by the wheel. The wall 80 diverges forwardly from the side wall 66, and there is an included angle of about degrees between them. As best shown in FIGURE 2, the outer wall 76 of the shroud is shaped to conform to the wall 80, and at the forward end of the latter, the outer wall 70 is cut back sharply to rejoin the right-hand wall es. Strips 79 of relatively thick steel are welded to the bottom edges of the shroud members 65, 70 and 80 at the end adjacent the wheels 16, 1'7, and these serve as stone guards to protect the bottom edge of the shroud from being damaged by flying stones thrown upwardly by the cutter Wheel 50.

The housing 46 is swingable vertically about the shaft 36, which causes the cutting wheel 50 and shroud 53 to move up and down with respect to the ground. The cutting wheel assembly is raised and lowered by means of a lifting lever 81, which is pivoted at 82 on a supporting bracket 83, mounted on the frame 12. A latch 87 on the lifting lever engages a toothed sector 84 on the bracket 83 to lock the lifting lever in adjusted position. The latch 87 is disengaged from the sector 84 by means of a latch-release rod 85. The latch-release rod 85 is slidably mounted on the lifting lever 81, and is pulled downwardly by a spring 86 to engage the latch 87 with the sector 84. A bell crank lever arm 90 projects forwardly from the pivot shaft 82, and connected to its outer end is a downwardly projecting link 91, the bottom end of which is connected at 92 to a bracket on the housing 40. Thus, when the lifting lever 81 is swung about its pivot 82, the housing with the cutting wheel and shroud 63 are raised or lowered, so as to adjust the depth to which the wheel 50 cuts.

When the machine is idle, or is being transported, the cutting wheel 50 is normally raised clear of the ground, and is locked in elevated position by the latch 87 and lever 81. The machine is usually pushed to one end of the line along which the trench is to be dug, and is positioned with handles 14, 15 facing forwardly along the line of travel. The gasoline engine 23 is then started, and the clutch 25 is engaged to start the wheel 59 rotating. The latch 87 is released, and the cutting wheel 50 is slowly lowered into the ground by lever 81. When the cutting wheel 50 is down to the desired depth, the latch 87 is allowed to engage the sector 84, thereby locking the wheel at the required depth. The machine is pulled rearwardly by the operator, who may follow a guide line previously marked on the ground, or he may rely merely on judgment to steer the desired course. Asthe cutting wheel 50 rotates at high speed, the blades cut a narrow slot through the ground and hurl the pulverized soil tangentially against the outer wall 70. The flying soil follows the curvature of the outer wall 70 and is deflected laterally to the right by the spiral ramp deflector plate 73, and out through the opening defined by the edge 71. The flying soil is additionally deflected laterally outward by the angled deflector plate 72, and is confined and guided by the outer deflector wall 80. At the exit opening of the shroud, most of the velocity of the soil is spent, and the pulverized soil drops to the ground alongside the trench in aneat, compact pile, where it is conveniently available to push back into the trench to cover the water pipe after the latter has been laid in place. As the machine reaches the end of the line, the lifting lever 81 is pulled back, which raises the wheel 50 out of the ground.

While we have shown and described in considerable detail what we believe to be the preferred form of our invention, it will be understood by those skilled in the art that various changes may be made in the shape and arrangement of the several parts without departing from the broad scope of the invention as defined in the following. claims.

We claim:

1. A trench-digging machine comprising:

a frame supported at one end on a pair of laterally spaced wheels, and at the other end on a single wheel, said single wheel being offset to one side of the foreand-aft centerline of the machine;

an internal combustion engine mounted on said frame;

a housing supported at one end on said frame for vertical swinging movement;

a transverse shaft journaled on said housing at the other end thereof;

power transmission means connecting said engine to said shaft, whereby the latter is driven by the engine;

a cutting wheel mounted on said shaft alongside said housing;

said cutting wheel having a plurality of generally radially extending blades mounted thereon;

each of said blades being inclined at an angle to the plane of said cutting wheel, whereby soil particles impacted by said blades are thrown tangentially outwardly and to one side of said cutting wheel;

a protective shroud mounted on said housing and enclosing the upper portion of said cutting wheel;

said shroud having a pair of generally parallel side walls on opposite sides of said cutting wheel, and an arcuately curved outer wall bridging the space between said side walls;

one of said side walls on the side toward which soil particles are thrown by said angled blades having a sector removed therefrom adjacent the point where said blades leave the ground, thereby providing an exit opening through which the soil particles are hurled by said blades;

a spiral ramp deflector mounted in said shroud in the area of said sector, one end of said spiral ramp being joined to said one side wall along one edge of said exit opening, and the other end thereof being joined to the other side wall;

an angled deflector plate mounted on said one side wall adjacent said one end of said spiral ramp; and

a deflector wall mounted on said shroud to the outside of said exit opening, said deflector wall being set at an angle to said one side wall and diverging forwardly with respect thereto;

said shroud enclosing and confining the particles of soil thrown tangentially and laterally outwardly'by said inclined blades, and said spiral ramp deflector and angled deflector plate deflecting said particles so that they drop to the ground in a narrow strip closely alongside the trench dug by said cutting wheel.

2. A trench-digging machine comprising:

a frame supported at one end on a pair oflaterally spaced wheels, and at the other end on a single wheel, said single wheel being offset to one side of the foreand-aft centerline of the machine;

an internal combustion engine mounted on said frame;

a housing supported at one end on said frame for vertical swinging movement;

a transverse shaft journaled on said housing at the other end thereof;

power transmission means connecting said engine to said shaft, whereby the latter is driven by the engine;

a star-shaped cutting wheel mounted on said shaft alongside said housing, said star-shaped Wheel having a plurality of equidistantly spacer star points;

each of said star points having a leading edge which is inclined back at a small angle from a radial line drawn through the center of said wheel;

a backing plate mounted on said leading edge of each of said star points, said backing plate being inclined at an angle of about 60 degrees to the plane of said wheel;

a blade mounted on the front face of each of said inclined backing plates, each of said blades having a forwardly bent lip at its outer end;

a protective shroud mounted on said housing and enclosing the upper half of said cutting wheel, said shroud having an exit opening in one side wall thereof; and

deflector means on said shroud positioned to be impacted by the particles of soil hurled tangentially and laterally outwardly by said inclined blades, said deflector means acting to guide said soil particles out through said exit opening, and to drop them onto the ground in a narrow strip alongside the trench dug by said cutting wheel.

3. A trench-digging machine as described in claim 1,

having a depth-adjusting lever swingably supported on said frame;

a bell crank arm extending generally horizontally from said depth-adjusting lever;

a link connected to the outer end of said bellcrank arm and to said housing at a point spaced radially outward from the pivot center thereof, whereby said housing with said cutting wheel carried at the outer end thereof, can be raised or lowered by said depthadjusting lever; and

means for locking said depth-adjusting lever at any adjusted position.

4. A trench-digging machine comprising:

a frame supported at one end on a pair of laterally spaced wheels, and at the other end on a single wheel, said single Wheel being offset to one side of the foreand-aft centerline of the machine;

an internal combustion engine mounted on said frame with the drive shaft thereof extending transversely with respect to the direction of forward travel;

a rotatable shaft mounted transversely on said frame between said pair of wheels and said single wheel;

speed-reduction power transmitting means connecting said drive shaft of said engine with said rotatable shaft;

an elongated housing mounted at one end on said rotatable shaft for vertical swinging movement and extending alongside said single wheel;

a shaft journaled on the other end of said housing and projecting laterally therefrom on the side opposite said single Wheel;

a driving connection between said rotatable shaft and said last-named shaft;

a cutting wheel mounted on the projecting end of said last-named shaft;

a plurality of generally radially extending blades mounted on said cutting wheel;

a protective shroud mounted on said housing and enclosing the upper half of said cutting wheel, said shroud having an exit opening in one side Wall thereof; and

deflector means on said shroud positioned to be impacted by particles of soil thrown by said blades, said deflector means acting to guide said soil particles out through said exit opening and to drop them onto the ground in a narrow strip alongside the trench dug by said cutting wheel.

References Cited by the Examiner UNITED STATES PATENTS 2,778,233 1/1957 Perry 17242 X 2,798,314 7/1957 Brite 3794 2,979,837 4/1961 Hunter 37--94 2,997,276 8/1961 Davis 3786 X 3,001,303 9/ 1961 Frederick 3794 3,055,438 9/1962 Wood et al. 17215 3,057,411 10/1962 Carlton 172-15 ABRAHAM G. STONE, Primary Examiner.

RAYMOND L. HOLLISTER, Assistant Examiner. 

4. A TRENCH-DIGGING MACHINE COMPRISING: A FRAME SUPPORTED AT ONE END ON A PAIR OF LATERALLY SPACED WHEELS, AND AT THE OTHER END ON A SINGLE WHEEL, SAID SINGLE WHEEL BEING OFFSET TO ONE SIDE OF THE FOREAND-AFT CENTERLINE OF THE MACHINE; AN INTERNAL COMBUSTION ENGINE MOUNTED ON SAID FRAME WITH THE DRIVE SHAFT THEREOF EXTENDING TRANSVERSELY WITH RESPECT TO THE DIRECTION OF FORWARD TRAVEL; A ROTATABLE SHAFT MOUNTED TRANSVERSELY ON SAID FRAME BETWEEN SAID PAIR OF WHEELS AND SAID SINGLE WHEEL; SPEED-REDUCTION POWER TRANSMITTING MEANS CONNECTING SAID DRIVE SHAFT OF SAID ENGINE WITH SAID ROTATABLE SHAFT; AN ELONGATED HOUSING MOUNTED AT ONE END ON SAID ROTATABLE SHAFT FOR VERTICAL SWINGING MOVEMENT AND EXTENDING ALONGSIDE SAID SINGLE WHEEL; A SHAFT JOURNALED ON THE OTHER END OF SAID HOUSING AND PROJECTING LATERALLY THEREFROM ON THE SIDE OPPOSITE SAID SINGLE WHEEL; A DRIVING CONNECTION BETWEEN SAID ROTATABLE SHAFT AND SAID LAST-NAMED SHAFT; A CUTTING WHEEL MOUNTED ON THE PROJECTING END OF SAID LAST-NAMED SHAFT; A PLURALITY OF GENERALLY RADIALLY EXTENDING BLADES MOUNTED ON SAID CUTTING WHEEL; A PROTECTIVE SHROUD MOUNTED ON SAID HOUSING AND ENCLOSING THE UPPER HALF OF SAID CUTTING WHEEL, SAID SHROUD HAVING AN EXIT OPENING IN ONE SIDE WALL THEREOF; AND DEFLECTOR MEANS ON SAID SHROUD POSITIONED TO BE IMPACTED BY PARTICLES OF SOIL THROWN BY SAID BLADES, SAID DEFLECTOR MEANS ACTING TO GUIDE SAID SOIL PARTICLES OUT THROUGH SAID EXIT OPENING AND TO DROP THEM ONTO THE GROUND IN A NARROW STRIP ALONGSIDE THE TRENCH DUG BY SAID CUTTING WHEEL. 